Insulator.



UNI ED STATES PATENT OFFICE.

THOMAS FORTUNE PURVES, OF WANDSWORTH, LONDON, AND JOHN SINNOTT, OF EAST FINGHLEY, LONDON, ENGLAND.

INSULA'IOR.

Application filed February 3, 1908.

To all whom it may concern:

Be it known that we, THOMAS Fon'rusu Punvns and JonN SiNNoT'r, subjects of the King of Great Britain, residing at 2] Vv'iiidmill road, "andsworth, London, S. \i., Eng land, and 74 Lincoln road, East Finchley, London, N., England, respectively, have invented certain new and useful Improvements in Electrical Insulators for Telephone or Telegraph Wires and the Like, of which the following is a specification.

This invention has reference to what are commonly known as leading-in or distributing insulators to which the ends of open or bare line or circuit wires are attached, and from which the covered or insulated leading in wires or cables proceed into a building or the like for the purpose of connecting up a telephone, telegraph or other instrument to the said line or circuit wires.

The leading-in cables employed in the usual metallic circuits of telephone and like systems are generally of the fibrous-core type in which two (or more) conductors are insulated with cotton, paper or other moisture-resisting material and are collectively sheathed in a lead or other metallic covering, and in connecting the ends of such cables with the line-wires it is essential to make some provision for sealing the cable so as to prevent the access of moisture to the condoctors.

The course usually adopted is to terminate the leading-in cable in an air-tight connection box or fittin which is se arate or distinct from the hne-wire insu ators and is filled with some insulating compound and to make the connection, within the said box, between the separated individual conductors of the leadin in cable and certain wires which procee from the box to the openwire insulators and are covered with guttapercha, indie-rubber or other anhydrous insulating material. The use of such separate insulating boxes or the like necessarily involves considerable expense in their installation and maintenance, and further, the employment of rubber-sheathed conductors between the boxes and the line-wire insulators is a disadvantage, both in respect of their cost and of the tendency of the insulating coverings to erish or deteriorate under atmos heric in uence.

Specification of Letters Patent.

T 10 object of the present invention is to Patented Sept. 15, 1908.

Serial No. 414,114.

obviate these dismh'antagcs by dispensing entirely with the use of separate connection or junction boxes or the like and their rubbereovered external conductors, and l ry making provision for the insulation and scaling of the individual and separated conductors of a duplex or multiple lead. shcathed cable actually within the leading-in insulator itself, and in such a simple but cllcctive manner that the access oi moisture lo the said cable is entirely prevented and all risk of electrical leakage between the separate conductors of the cable, or between the external wires and the covering or sheath of the cable, is obviated, in addition to which, the separated and insulated conductors of the cable can be directly connected to the bare line-wires which are carried from the said insulators. Thus, we propose to form or provide within the top of a leading-in lllSlllz'tt-Ol, cablescaling or insulation chamber or cavity into which the lead-sheathed cable is introduced through a suitable passage, and wherein the inner ends of the individual conductors contained in said cable are separated from one another after being stripped from the sheathing and then passed respectively through suitable holes or openings running from the sealing cavity or chamber to the exterior of the insulator, where the said conductors are connected with the naked line-wires.

The sealing and insulation of the end of the sheathed cable and the complete isolation of the stripped and separated conductors from one another and also from the metallic sheathing is effected by filling the chamber or cavity with wax or other non-conducting material or composition which not only seals up, the end of the sheathing and runs between the parts of the separated'conductors that lie in the said chamber, but also fills up the holes or passages leading from the chamher to the exterior of the insulator and thus efl'ectually excludes the wet and prevents moisture from creeping from the outside of the said insulator to any part of the cable or conductors that are located within it.

In Figures 1 to S of the accompanying drawings, we represent one form of our improved leading-in insulator which is adapted to carry both. the bare line-wires oi an ordinary metallic telephone circuit, while Figs. 9 and 10 represent a modified form of insulator which is designed. to carry only one of the said line wires but provides for the connection of one of the conductors of the cable to the second line wire which is carried from an independent insulator so as to provide for high insulation between the said conductors. Referring to the arrangement shown in Figs. 1 to 8; Fig. 1 represents an elevation of the improved insulator but the upper part is drawn in section so as to show more clearly the arrangement of the sealing chamber or cavity and of the passages that are provided for the reception of the lead-sheathed leading-in cable and of the separated conductors which are connected respectively to the two bare line-wires that are attached to the said insulator. Fig. 2 is another sectional elevation showing the insulator rotated through an angle of 90 degrees from. the position shown in Fig. 1. Fig. 3 is a complete vertical section of the insulator body, without the cap, the section being taken through the passage which is provided for the running of the lead-sheathec part of the cable from the sealing chamber. Fig. 4 is a plan of Fig. 3. Figs. 5, 6, and 7 show three different horizontal sections of the insulator, taken respectively upon the dotted lines :5 11: and m, Fig. 1. Fig. 8 shows one horizontal section of the sealing box without its filling of insulating material.

The same letters of reference indicate corres ending parts in Figs. 1 to 8.

he body a of the insulator is of substantially the ordinary form and has two petticoats a, 0, with an intermediate shed a also a screwed axial socket at a to rovide for its attachment to an insulator' olt or spindle. In the top of this bed part there is sunken, a circular cavity or c amber b of suitable dimensions, over which a cap or cover 0 is screwed to com lete the said cavity, into which the lead-s eathed cable (1 is introduced by wa of a hole or passage 6 formed through t e body of the insulator and leading from the top of the shed a, into the bottom of the said cavity, while to provide for the conveyance of the stripped and separated conductors (1, d of the said cable respectively to the two bare line-wires f g which are run round and secured within grooves f, g, on the outside of the insulator, two other holes or passages e, e are directed obliquely from the cavity and terminate respectively in the said grooves f, g.

As will be seen from the drawings, the sheathed part of the cable terminates in the cavity 1) and the conductors (1 d are separated and passed respectively through the passages e, 6, so that the stripped or bared extremities of the wires extend through the outer ends ,of the said passages and are connected to the line wires that lie within the grooves f, g. i

To seal the end of the cable and insulate the separated conductors from one another,

as well as to exclude moisture, the cavity is' com letely filled with wax or other noncon ucting material, which is referabl run-in in a molten condition so t at it wi l.

flow into the passages e e and completely fill up any spaces that might otherwise be left between the wires and the inside of said passage so that it is impossible for any moisture to creep up the passages into the cavity and obtain access to the sealed parts of the cable and conductors. After the fill ing of the cavity, the cap or cover is screwed on as shown in Fig. l.

The improved insulator may be adapted for carrying any number of wires and connecting same with the separated conductors of a cable by forming a suitable number of grooves around the exterior of the insulator and providing conductor passages or holes from each of the said grooves into the sealing cavity or chamber.

In the modified form of sealing insulator shown in Figs. 9 and 10 two cable passages, e, e, are formed between the shed a and the sealing cavity b and only one of the external grooves is connected with the said cavity by the passage e. The sheathed duplex or multiple-conductor cable d is passed throu h the shed a and up the passage e into t e cavity 1) where its conductors are se arated, sealed and insulated by the filling o wax as in the previously described arrangement. One of these conductors (Z is passed out through the passage e and connected to the line-wiref in the groove f, whereas the other conductor is connected to a sheathed or insulated single conductor d which is directed from the sealing-chamber down the passage 6 into the shed and may be taken on to a second insulator or otherwise. In this modification the wax filling in the sealing chamber serves to seal and insulate the connection between the one conductor of the cable (1 and the single sheathed conductor (i as well as to seal and insulate that conductor ((1 which is run through the passage e to the outside line wire. Any number of holes or passages may be formed between the shed and the sealing chamber or cavity, according to the number of single sheathed conductors which are re uired to be connected up with the se arate conductors of the multiple cable, ut in every case the whole of the connections are sealed and insulated when the said chamber or cavity is filled with the nonconducting material. If necessary, the bottom of the sealing cavity of the insulator shown in Figs. 1 to 8, may be provided with grooves h, h, in which the se arated conductors are laid to keep them we 1 apart.

It is admittedly not new to rovide an electric insulator of the double be type with two perforations running from the shed t0 the top of the insulator to enable a single connecting wire, covered with anhydrous material, to be assed up the one erforation, over the said insulator top, an down the other perforation; also to admit of a portion of the said insulator being protected from ex osure to weather and consequent surface lea lrage by means of a ca which is screwed onto the said top, but suc insulators are not adapted for making and sealing and insulating junctions between the separated conductors of a sheathed duplex or multiple cable, neither do they provide for dealing with more than one wire running in and out.

Having fully described our invention, what we desire to claim and secure by Letters Patent is:

1. A leading-in insulator for telephone and other electrical wiring systems, rovided with a sealing chamber or cavit a apted to be filled with insulating materia and a series of holes or passages directed into said chamber from the outside of the insulator, one of the said holes roviding for the introduction of a sheathed c uplex or multi 1e conductor cable into the sealing-cham er, while the other holes rovide for the connection of the said cable, ductors of the cable, to two or more line-wires which are attached to the exterior of the said insulator, substantiall 2. An insulator of t e type set forth comprising a body portion formed with a chamer and with a cable passage extending into said chamber from the exterior of said insulator, said chamber bein for the reception of an insulating agent, sai body portion having wire passages extending from said chamy the separated individual con-- as herein described' ber to the outer face of said body portion, and a closure for said chamber.

3. An insulator of the t pe set forth comrising a body having a c amber to contain insulating material, said body having a cable passa e extending from the exterior to said cham er and havin a wire passage extending from said cham%)er to its exterior face, and a closure for said chamber.

4. An insulator of the type set forth comprising a body portion constructed with an interior chamber to receive an insulating agent and with passages extendin to and communicating 'with said chamber from the outer face of said body portion, as and for the purpose set forth.

5. An insulator of the type set forth comprising a body portion constructed with a chamber to contain an insulating agent, said body portion being formed with spaced pettieoats and with an annular groove in its outer face, said body ortion having a cable passage extending rom a point between said pettieoats to and in communication with said chamber and having a wire passage extending from said chamber to and in communication with said groove, as and for the purpose set forth.

In testimony whereof we have hereunto set our hands in presence of two subscribing witnesses.

THOMAS FORTUNE PURVES. JOHN SINNOTT. Witnesses:

T. L. RAND, H. D. JAMESON. 

